What do you guys mean 21m bitcoin is the totall and we are at 13 million ? what will happen when we reach 21m ?

I don't understand your question.

After block 6930000, all the new bitcoins will have been created. At that point, there will have been nearly 20999999.9769 BTC created. People will just have to use the bitcoins that already exist, since there won't be any more created after that.

Well, if everything works out fine, Bitcoin will be worth quite a bit then and transaction fees are able to pay miners for their work. If mining becomes unprofitable, less people will mine, but there's no harm in that.

Well, if everything works out fine, Bitcoin will be worth quite a bit then and transaction fees are able to pay miners for their work. If mining becomes unprofitable, less people will mine, but there's no harm in that.

Chances are:1. Bitcoin price will go up 2. Tx fee will go up 3. Number of miners will go down4. Big bitcoin holders will mine at loss to support mining5. A combination of the above